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Stifflers

FIT Subframe System Chassis Stiffening Kit

$569.95 $559.99 Save $9.96

SKU: FIT-M02

In Stock
In Stock
Ships by Jul 29
Free Shipping
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The Stifflers FIT Subframe System is a modular chassis stiffening kit designed for 1979-1993 Mustangs. It integrates subframe connectors, stiffening rails, and a web brace to enhance chassis stiffness and strength. This system is optimized to improve ride quality, handling, and suspension tuning range by reducing chassis twisting.

The FIT System is constructed from mild steel tubing and features a Slide-2-Size mounting system for easier installation of the web brace. The weld locations are free of powder coat to save preparation time. The non-intrusive design does not require floor cutting or interior removal, and it maintains factory ground clearance.

Fitment

Fitment Guaranteed

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on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandStifflers
Part NumberFIT-M02
CategoryChassis Components

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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